|Constructor and Description|
|Modifier and Type||Method and Description|
Map of hints (maybe unmodifiable) used by this factory to customize its use.
public boolean isAvailable()
trueif this factory is ready for use. An optional factory may returns
falsefor now but returns
truelater. However, the converse is not recommended.
public Map<RenderingHints.Key,?> getImplementationHints()
The primary purpose of this method is to determine if an existing
factory instance can be reused for a set of user-supplied hints. This method is invoked by
FactoryRegistry in order to compare this factory's hints against user's hints.
This is dependency introspection only;
invokes this method for creating new factories.
Keys are usually static constants from the
Hints class, while values are
instances of some key-dependent class. The key set must contains
at least all hints impacting functionality. While the key set may contains all hints
supplied by the user, it is recommended to limit the set to only the hints used by this
particular factory instance. A minimal set will helps
FactoryRegistry to compare
only hints that matter and avoid the creation of unnecessary instances of this factory.
The hint values may be different than the one supplied by the user. If a user supplied a
hint as a
Class object, this method shall replace it by the actual instance used,
Implementations of this method are usually quite simple. For example if a datum authority factory uses an ordinary datum factory, its method could be implemented as below (note that we should not check if the datum factory is null, since key with null value is the expected behaviour in this case). Example:
Map hints = new HashMap(); hints.put(Hints.DATUM_FACTORY, datumFactory); return hints;
Copyright © 1996–2018 Geotools. All rights reserved.